Factoring Trinomials Calculator

Factor quadratic trinomials using the AC method with step-by-step solutions

Quadratic Trinomial

Current Trinomial:

x² + 8x + 12

Standard form: ax² + bx + c

Factorization Result

Factorable
Status

Factored Form

(x -2)(x -6)
Discriminant (Δ)
16
Method
AC Method

Step-by-Step Solution

Original trinomial: 1x² +8x +12
Discriminant: Δ = b² - 4ac = 8² - 4(1)(12) = 16
Using AC method:
AC = a * c = 1 * 12 = 12
We need to find two numbers that multiply to 12 and add to 8
Factor pairs of AC:
-12 * -1 = 12, -12 + -1 = -13
-6 * -2 = 12, -6 + -2 = -8
-4 * -3 = 12, -4 + -3 = -7
1 * 12 = 12, 1 + 12 = 13
2 * 6 = 12, 2 + 6 = 8
✓ This pair works!
3 * 4 = 12, 3 + 4 = 7
Since a = 1, we can factor directly:
1x² +8x +12 = (x -2)(x -6)

Example Problems

Example 1: Simple Case (a = 1)

Trinomial: x² + 8x + 12

AC Method: Find two numbers that multiply to 12 and add to 8

Pair: 2 * 6 = 12, 2 + 6 = 8

Result: (x + 2)(x + 6)

Example 2: General Case

Trinomial: 2x² + 7x + 3

AC Method: AC = 2 * 3 = 6, find pair that adds to 7

Pair: 1 * 6 = 6, 1 + 6 = 7

Result: (2x + 1)(x + 3)

Example 3: Perfect Square

Trinomial: x² + 6x + 9

Pattern: a² + 2ab + b² = (a + b)²

Result: (x + 3)²

AC Method Steps

1

Calculate AC

Multiply coefficients a and c

2

Find Factor Pairs

List all pairs that multiply to AC

3

Check Sums

Find pair that adds to coefficient b

4

Factor by Grouping

Rewrite and factor the expression

Quick Tips

Discriminant: Δ = b² - 4ac determines if factorization exists
Perfect Square: Look for pattern a² + 2ab + b²
Common Factors: Factor out GCD first if possible
Sign Rules: AC > 0 means same signs, AC < 0 means different signs

Understanding Trinomial Factoring

What is a Quadratic Trinomial?

A quadratic trinomial is a polynomial of degree 2 with three terms, written in the form ax² + bx + c where a, b, and c are real numbers and a ≠ 0. Factoring means finding two linear binomials that multiply to give the original trinomial.

The AC Method

The AC method (also called factoring by grouping) is a systematic approach to factor quadratic trinomials. It involves finding two numbers whose product equals AC and whose sum equals B, then using these to rewrite and factor the expression.

Special Cases

Perfect Square Trinomial

a² + 2ab + b² = (a + b)²

Difference of Squares

a² - b² = (a + b)(a - b)

Common Factor

Factor out GCD first, then proceed

When Can't We Factor?

Δ

Negative Discriminant

When Δ = b² - 4ac < 0

No Integer Factors

No integer pair satisfies the conditions

Irrational Roots

Roots exist but are not rational